UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Towards accurate partial volume correction in (99m}^Tc oncology SPECT: perturbation for case-specific resolution estimation

Gillen, Rebecca; Erlandsson, Kjell; Denis-Bacelar, Ana M; Thielemans, Kris; Hutton, Brian F; McQuaid, Sarah J; (2022) Towards accurate partial volume correction in (99m}^Tc oncology SPECT: perturbation for case-specific resolution estimation. EJNMMI Physics , 9 (1) , Article 59. 10.1186/s40658-022-00489-5. Green open access

[thumbnail of s40658-022-00489-5.pdf]
Preview
Text
s40658-022-00489-5.pdf - Published Version

Download (3MB) | Preview

Abstract

BACKGROUND: Currently, there is no consensus on the optimal partial volume correction (PVC) algorithm for oncology imaging. Several existing PVC methods require knowledge of the reconstructed resolution, usually as the point spread function (PSF)-often assumed to be spatially invariant. However, this is not the case for SPECT imaging. This work aimed to assess the accuracy of SPECT quantification when PVC is applied using a case-specific PSF. METHODS: Simulations of SPECT [Formula: see text]Tc imaging were performed for a range of activity distributions, including those replicating typical clinical oncology studies. Gaussian PSFs in reconstructed images were estimated using perturbation with a small point source. Estimates of the PSF were made in situations which could be encountered in a patient study, including; different positions in the field of view, different lesion shapes, sizes and contrasts, noise-free and noisy data. Ground truth images were convolved with the perturbation-estimated PSF, and with a PSF reflecting the resolution at the centre of the field of view. Both were compared with reconstructed images and the root-mean-square error calculated to assess the accuracy of the estimated PSF. PVC was applied using Single Target Correction, incorporating the perturbation-estimated PSF. Corrected regional mean values were assessed for quantitative accuracy. RESULTS: Perturbation-estimated PSF values demonstrated dependence on the position in the Field of View and the number of OSEM iterations. A lower root mean squared error was observed when convolution of the ground truth image was performed with the perturbation-estimated PSF, compared with convolution using a different PSF. Regional mean values following PVC using the perturbation-estimated PSF were more accurate than uncorrected data, or data corrected with PVC using an unsuitable PSF. This was the case for both simple and anthropomorphic phantoms. For the simple phantom, regional mean values were within 0.7% of the ground truth values. Accuracy improved after 5 or more OSEM iterations (10 subsets). For the anthropomorphic phantoms, post-correction regional mean values were within 1.6% of the ground truth values for noise-free uniform lesions. CONCLUSION: Perturbation using a simulated point source could potentially improve quantitative SPECT accuracy via the application of PVC, provided that sufficient reconstruction iterations are used.

Type: Article
Title: Towards accurate partial volume correction in (99m}^Tc oncology SPECT: perturbation for case-specific resolution estimation
Location: Germany
Open access status: An open access version is available from UCL Discovery
DOI: 10.1186/s40658-022-00489-5
Publisher version: https://doi.org/10.1186/s40658-022-00489-5
Language: English
Additional information: © 2022 BioMed Central Ltd. This article is licensed under a Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/).
Keywords: Partial volume correction, Perturbation, Quantification, SPECT
UCL classification: UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Div of Medicine > Department of Imaging
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Div of Medicine
URI: https://discovery.ucl.ac.uk/id/eprint/10155323
Downloads since deposit
27Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item